In the prior art, devices formed by brushes which slide in housings or grooves carried by a brush holder plate are known.
The carbons or brushes are applied by springs against the surface of a commutator mounted on a rotating shaft connected to the rotor of the motor, which passes through a bore in the plate.
The plate comprises strip conductors, for example, and possibly electrical components, and also a connector to an electricity supply cable.
In the prior art, such plates are formed by an insulating plate on which are disposed conductive components and also the various components described above.
Because of the plane nature of the plate, a problem is encountered when performing the assembly of the plate onto the casing of the electric motor.
In fact, the plate bearing the brushes or carbons has to be appropriately orientated in relation to the electric and/or magnetic axis of the motor. Furthermore, the position assumed by the plate along the axis of the rotor has to correspond to an optimal contact position between the brushes and the commutator.
In particular, during the assembly of the brush holder plate, a certain number of tests have to be performed to decide the right-left orientation in relation to an axis, a plane or a winding direction, etc.
These operations are expensive in assembly time and there is the risk of errors which are translated, for large scale production, into a certain reject rate.